[200q20v] Tour Around the Engine (long)

[Forhan, Thomas]

Make good progress on what I am begining to think of as my  "tour round the
engine" project, which covers all the things that should have been done by
the DPO (damn previous owner). 

This weeked I installed  new air and fuel filters, pulled and cleaned the
throttle body, put on new throttle potentioment (throwing error codes, does
not have a smooth curve on an oscilloscope), and replaced the crankcase
breather hose. I also stripped the front of the car for the timing belt,
water pump and front crankcase seal replacement.  

Parts that should arrive this week, hopefully for installation over next
weekend: distibutor cap and proper rotor (thanks Derek), OEM spark plug
wires, proper plugs, O2 sensor, plus the Blau timing belt kit and three new
accessory belts. I also rented Blau's tool kit for the belt job. 

Lessons learned so far:

That aircleaner screw- I looked all over with a mirror in a location
analogous to the three spring clamps, but it was right in front of me, yuo
have to look down along side the fender. This has been a FAQ, but the
location is non-inuitive to me and if someone has a digital camera, a
picture would be worth a thousand words.

Removal of the throttle body. This is written up in bits and pieces in the
archives, and I got good help from the list last week, but here is a step by
step: This is vaguely a half hour job.

1) Loosen two clamps connecting the big black tube thing on the passenger
side of the engine that leads between the intercooler and the throttle body
(I don't now what this thing is called-I'll call it the plenum) First clamp
is on  the Michelin man hose end (I disconnected at the intercooler), the
other is right at the throttle body. 
2)Remove two bolts and one nut (or was it two nuts and one bolt, anyway,
they were all 13mm) holding the plenum thingy on near the heat protection
shield. 3)3)Remove the small (3/8" hose that runs alongside the plenum,
connecting the turbo bypass valve and the messo-hoses behind the idle
stabilization valve. 
4)Remove the plenum - I pulled on the front, then the back, and back and
forth, and it came out pretty easily.
5)Disconnect the throttle linkage. There are two sheet metal spring clamps,
after prying them off carefully you can unthread the actual cable.
6)Disconnect the cruise control linkage - the rigid rod with a ball socket
on it. Look very carefully at the socket and you will see a tiny wire clip
the restricts the ball from falling out of the socket. Pry/push the clip
down to open it up and disconnect.
7)Optional, I guess, I also pulled off the throttle stop bracket from the
throttle body, two 6 mm hex heads as I recall, to make things less
cluttered.
8)Remove four six mm hex head screws holding on the body. The lower forward
one does not have clearance for my 3/8 drive hex sockets, so I had to use a
regular allen wrench. 
9)Gently pull the throttle body off and you may save the gasket.


I was glad I did this because the throttle body was mucked up with oil and I
could clean it,  the throttle pot mounting screws had both been damaged and
replacement was really easy with it out, and finally, it made it really easy
to replace the crankcase breather hose. 

Breather hose replacement: I took hints from other listers on this, and
disconnected the whole assembly: at the breather, natch, but also I removed
the associated hoses running from the intake manifold, and I disconnected
the  electrics and small tube from the carbon canister so that would come
out with the breather hose, as well as the bypass valve at the passenger
side. 

I cut the breather hose about three inches above the breather, removed the
upper piece and all the associated tubes, and then carefully cut away the
last bit at the block: as other have said, this hose can be a mess and be
sure you don't get any old rubber into the crankcase.

I then laid old and new hoses side by side, and transfered the relevant tee
connection and the carbon cannister. I cut open the skinny end of the old
hose and removed the copper flame arrester, put it into the new hose and
clamped on the valve. Using the space created by the throttle body removal,
I worked the big hose in place, reconnected the small hose to the intake
manifold, reconnected the carbon canister, and the valve on the passenger
side. Finally, put the big hose onto the breather on the block. 

With the throttle body out of the way, I will say that replacing the
breather hose, though a little messy, is pretty easy.

No problems with stripping the front of the car for the timing belt. I was
stopped dead by removal of the intake manifold, however, for access to the
distributor. The Bentley has great directions on this, but I could not find
a 1/4" drive extension long enough to pass through the holes on the manifold
to bring a 6mm hex head to bear. I'm really going to try to find the long
hex tool VAG 1669, or an equivalent, because I can see this will be much,
much easier to do this with the proper tool.

Tom F.